Method and system for controlling an operation of a communication network to reduce latency

ABSTRACT

The method includes transmitting request messages to at least one first network node, the request messages each including at least a sampling time-window and a network slice identifier, the sampling time-window defining a duration of time, the network slice identifier identifying a designated network slice within the communication network, receiving packet reports from the at least one first network node, the packet reports including latency information for packets that are processed by the at least one first network node during the sampling time-window for the designated network slice, and controlling the operation of the communication network based on the latency information.

BACKGROUND Field

Example embodiments relate generally to a method and a system forcontrolling an operation of a communication network by measuring andmonitoring network latency. The method and system have applicability topacket-switched networks, including 5^(th) generation wirelesscommunication networks (5G networks).

Related Art

Communication networks continuously receive new service demands from avariety of users, machines, industries, governments, and otherorganizations. In a 5^(th) generation wireless communication network (5Gnetwork), new services will be supported and enabled by dedicated,secure, customized end-to-end network slices. Network slices supporttheir associated services and ensure isolation of their traffic within ashared physical infrastructure by means of dedicated virtualized networkfunctions in the data and control planes.

Many of the new services and applications (for example, virtual reality(VR), network-assisted autonomous control of vehicles and drones,network-assisted automated factories and cities, remote robot control,remote surgery, etc.) have stringent end-to-end latency requirementswhile they generate “bursty” network traffic (i.e., traffic withintervals of high load demands). End-to-end latency is expected to be aprominent key performance indicator (KPI) in the service levelagreements (SLAs) associated with these services and their respectivenetwork slices.

SUMMARY

At least one example embodiment includes a method of controlling anoperation of a communication network.

In one example embodiment, the method includes transmitting, by at leastone first processor of a central node, request messages to at least onefirst network node, the request messages each including at least asampling time-window and a network slice identifier, the samplingtime-window defining a duration of time, the network slice identifieridentifying a designated network slice within the communication network;receiving, at the at least one first processor, packet reports from theat least one first network node, the packet reports including latencyinformation for packets that are processed by the at least one firstnetwork node during the sampling time-window for the designated networkslice; and controlling, by the at least one first processor, theoperation of the communication network based on the latency information.

In one example embodiment, the at least one first network node includesat least one first-type of network node with a first link in thedesignated network slice, the first link having a termination endpointthat is within the communication network.

In one example embodiment, the at least one first network node includesat least one second-type of network node with a second link in thedesignated network slice, the second link having a termination endpointthat is outside the network slice.

In one example embodiment, the receiving of the packet reports includes,receiving, from the first-type of network node, a first-type of packetreports for the designated network slice, the first-type of packetreports each including, packet identifier information, packet sizeinformation, and timestamp information.

In one example embodiment, the at least one first network node includesat least one first-type of network node with a first link in thedesignated network slice, the first link having a termination endpointthat is within the communication network, and the receiving of thepacket reports includes, receiving, from the first-type of network node,a first-type of packet reports for the designated network slice, thefirst-type of packet reports each including, packet identifierinformation, packet size information, and timestamp information; andreceiving, from the second-type of network node, a second-type of packetreports for the designated network slice, the second-type of packetreports each including latency information for the second-type ofnetwork node.

In one example embodiment, the network slice identifier identifies adirection of communication for the designated network slice, thedirection being one of an uplink direction and a downlink direction.

In one example embodiment, the central node and the first-type ofnetwork node are synchronized to a same network clock for thecommunication network, and the request messages to the at least onefirst-type of network node includes a start time defined by the samplingtime-window.

In one example embodiment, the at least one first-type of network nodeincludes a downstream first-type of network node and an upstreamfirst-type of network node, the transmitting of the request messagesincluding, transmitting a first request message with a first samplingtime-window to the downstream first-type of network node, the firstsampling time-window defining a first start time and a first duration oftime, and transmitting a second request message with a second samplingtime-window to the upstream first-type of network node, the secondsampling time-window defining a second start time and a second durationof time, the first duration of time being one of the same and differentthan the second duration of time.

In one example embodiment, the receiving of the packet reports includes,receiving a first packet report from the downstream first-type ofnetwork node, the first packet report including one first set of packetidentifier information associated with one first set of timestampinformation, and receiving a second packet report from the upstreamfirst-type of network node, the second packet report including onesecond set of packet identifier information associated with one secondset of timestamp information.

In one example embodiment, the method further includes calculating thelatency information by, matching identifier information between the onefirst set of packet identifier information and the one second set ofpacket identifier information to arrive at a matched subset ofidentifier information, and determining a difference between a firstportion of the one first set of timestamp information and a secondportion of the one second set of timestamp information, the first andsecond portions being associated with the matched subset of identifierinformation.

At least another example embodiment is directed toward, one exampleembodiment a method of controlling an operation of a communicationnetwork in a system, the system including a central node and at leastfirst network node.

In one example embodiment, the method includes transmitting, by at leastone first processor of the central node, request messages to at leastone second processor of the at least one first network node, the requestmessages each including at least a sampling time-window and a networkslice identifier, the sampling time-window defining a duration of time,the network slice identifier identifying a designated network slicewithin the communication network; creating, by the at least one secondprocessor, packet reports upon receipt of the request message, thepacket reports including latency information for packets that areprocessed by the at least one first network node during the samplingtime-window for the designated network slice; receiving, at the at leastone first processor, the packet reports from the at least one secondprocessor; and controlling, by the at least one first processor, theoperation of the communication network based on the latency information.

In one example embodiment, the at least one first network node includesat least one first-type of network node with a first link in thedesignated network slice, the first link having a termination endpointthat is within the communication network.

In one example embodiment, the at least one first network node includesat least one second-type of network node with a second link in thedesignated network slice, the second link having a termination endpointthat is outside the network slice.

In one example embodiment, the receiving of the packet reports includes,receiving, from the first-type of network node, a first-type of packetreports for the designated network slice, the first-type of packetreports each including, packet identifier information, packet sizeinformation, and timestamp information.

In one example embodiment, the at least one first network node includesat least one first-type of network node with a first link in thedesignated network slice, the first link having a termination endpointthat is within the communication network, and the receiving of thepacket reports includes, receiving, from the first-type of network node,a first-type of packet reports for the designated network slice, thefirst-type of packet reports each including, packet identifierinformation, packet size information, and timestamp information; andreceiving, from the second-type of network node, a second-type of packetreports for the designated network slice, the second-type of packetreports each including latency information for the second-type ofnetwork node.

In one example embodiment, the network slice identifier identifies adirection of communication for the designated network slice, thedirection being one of an uplink direction and a downlink direction.

In one example embodiment, the central node and the first-type ofnetwork node are synchronized to a same network clock for thecommunication network, and the request messages to the at least onefirst-type of network node includes a start time defined by the samplingtime-window.

In one example embodiment, the at least one first-type of network nodeincludes a downstream first-type of network node and an upstreamfirst-type of network node, the transmitting of the request messagesincluding, transmitting a first request message with a first samplingtime-window to the downstream first-type of network node, the firstsampling time-window defining a first start time and a first duration oftime, and transmitting a second request message with a second samplingtime-window to the upstream first-type of network node, the secondsampling time-window defining a second start time and a second durationof time, the first duration of time being one of the same and differentthan the second duration of time.

In one example embodiment, the receiving of the packet reports includes,receiving a first packet report from the downstream first-type ofnetwork node, the first packet report including one first set of packetidentifier information associated with one first set of timestampinformation, and receiving a second packet report from the upstreamfirst-type of network node, the second packet report including onesecond set of packet identifier information associated with one secondset of timestamp information.

In one example embodiment, the method further includes calculating thelatency information by, matching identifier information between the onefirst set of packet identifier information and the one second set ofpacket identifier information to arrive at a matched subset ofidentifier information, and determining a difference between a firstportion of the one first set of timestamp information and a secondportion of the one second set of timestamp information, the first andsecond portions being associated with the matched subset of identifierinformation.

In one example embodiment, the creating of the packet reports includes,calculating, by the at least one second processor of the at least onesecond-type of network node, physical resource block (PRB) rateinformation and bearer information that includes a quantification of anumber of very active bearers, and determining, by the at least onesecond processor, the latency information based on the PRB rateinformation and the bearer information.

At least another example embodiment is directed toward a central node.

In one example embodiment, the central nodes includes a memory storingcomputer-readable instructions; and at least one first processorconfigured to execute the computer-readable instructions such that theat least one first processor is configured to, transmit request messagesto at least one first network node, the request messages each includingat least a sampling time-window and a network slice identifier, thesampling time-window defining a duration of time, the network sliceidentifier identifying a designated network slice within thecommunication network, receiving packet reports from the at least onefirst network node, the packet reports including latency information forpackets that are processed by the at least one first network node duringthe sampling time-window for the designated network slice, and controlthe operation of the communication network based on the latencyinformation.

At least another example embodiment includes a system.

In one example embodiment, the system includes a central node including,a first memory storing first computer-readable instructions, and atleast one first processor configured to execute the firstcomputer-readable instructions such that the at least one firstprocessor is configured to, transmit request messages to the at leastone second processor, the request messages each including at least asampling time-window and a network slice identifier, the samplingtime-window defining a duration of time, the network slice identifieridentifying a designated network slice within the communication network;and at least one first network node including, a second memory storingsecond computer-readable instructions, and at least one second processorconfigured to execute the second computer-readable instructions suchthat the at least one second processor is configured to, create packetreports upon receipt of the request message, the packet reportsincluding latency information for packets that are processed by the atleast one first network node during the sampling time-window for thedesignated network slice, the at least one first processor being furtherconfigured to receive the packet reports from the at least one secondprocessor, and control the operation of the communication network basedon the latency information.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an architecture of a system for a communicationnetwork, in accordance with an example embodiment;

FIG. 2 illustrates a central (control) node of the system, in accordancewith an example embodiment;

FIG. 3 illustrates a first measurement node of the system, in accordancewith an example embodiment;

FIG. 4 illustrates a second measurement node of the system, inaccordance with an example embodiment;

FIG. 5 illustrates an instantiation of the system for latencymeasurement in a representative 5G communication network with multipleslices, in accordance with an example embodiment;

FIG. 6 illustrates a system for latency measurement in a mobile radioaccess network (RAN) communication network, in accordance with anexample embodiment;

FIG. 7 illustrates an operation of the first measurement node, inaccordance with an example embodiment; and

FIG. 8 illustrates a method of the central node, in accordance with anexample embodiment.

DETAILED DESCRIPTION

While example embodiments are capable of various modifications andalternative forms, embodiments thereof are shown by way of example inthe drawings and will herein be described in detail. It should beunderstood, however, that there is no intent to limit exampleembodiments to the particular forms disclosed, but on the contrary,example embodiments are to cover all modifications, equivalents, andalternatives falling within the scope of the claims Like numbers referto like elements throughout the description of the figures.

Before discussing example embodiments in more detail, it is noted thatsome example embodiments are described as processes or methods depictedas flowcharts. Although the flowcharts describe the operations assequential processes, many of the operations may be performed inparallel, concurrently or simultaneously. In addition, the order ofoperations may be re-arranged. The processes may be terminated whentheir operations are completed, but may also have additional steps notincluded in the figure. The processes may correspond to methods,functions, procedures, subroutines, subprograms, etc.

Methods discussed below, some of which are illustrated by the flowcharts, may be implemented by hardware, software, firmware, middleware,microcode, hardware description languages, or any combination thereof.When implemented in software, firmware, middleware or microcode, theprogram code or code segments to perform the necessary tasks may bestored in a machine or computer readable medium such as a storagemedium, such as a non-transitory storage medium. A processor(s) mayperform the necessary tasks.

Specific structural and functional details disclosed herein are merelyrepresentative for purposes of describing example embodiments. Thisinvention may, however, be embodied in many alternate forms and shouldnot be construed as limited to only the embodiments set forth herein.

It will be understood that, although the terms first, second, etc. maybe used herein to describe various elements, these elements should notbe limited by these terms. These terms are only used to distinguish oneelement from another. For example, a first element could be termed asecond element, and, similarly, a second element could be termed a firstelement, without departing from the scope of example embodiments. Asused herein, the term “and/or” includes any and all combinations of oneor more of the associated listed items.

It will be understood that when an element is referred to as being“connected” or “coupled” to another element, it can be directlyconnected or coupled to the other element or intervening elements may bepresent. In contrast, when an element is referred to as being “directlyconnected” or “directly coupled” to another element, there are nointervening elements present. Other words used to describe therelationship between elements should be interpreted in a like fashion(e.g., “between” versus “directly between,” “adjacent” versus “directlyadjacent,” etc.).

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of exampleembodiments. As used herein, the singular forms “a,” “an” and “the” areintended to include the plural forms as well, unless the context clearlyindicates otherwise. It will be further understood that the terms“comprises,” “comprising,” “includes” and/or “including,” when usedherein, specify the presence of stated features, integers, steps,operations, elements and/or components, but do not preclude the presenceor addition of one or more other features, integers, steps, operations,elements, components and/or groups thereof.

It should also be noted that in some alternative implementations, thefunctions/acts noted may occur out of the order noted in the figures.For example, two figures shown in succession may in fact be executedconcurrently or may sometimes be executed in the reverse order,depending upon the functionality/acts involved.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which example embodiments belong. Itwill be further understood that terms, e.g., those defined in commonlyused dictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

Portions of the example embodiments and corresponding detaileddescription are presented in terms of software, or algorithms andsymbolic representations of operation on data bits within a computermemory. These descriptions and representations are the ones by whichthose of ordinary skill in the art effectively convey the substance oftheir work to others of ordinary skill in the art. An algorithm, as theterm is used here, and as it is used generally, is conceived to be aself-consistent sequence of steps leading to a desired result. The stepsare those requiring physical manipulations of physical quantities.Usually, though not necessarily, these quantities take the form ofoptical, electrical, or magnetic signals capable of being stored,transferred, combined, compared, and otherwise manipulated. It hasproven convenient at times, principally for reasons of common usage, torefer to these signals as bits, values, elements, symbols, characters,terms, numbers, or the like.

In the following description, illustrative embodiments will be describedwith reference to acts and symbolic representations of operations (e.g.,in the form of flowcharts) that may be implemented as program modules orfunctional processes include routines, programs, objects, components,data structures, etc., that perform particular tasks or implementparticular abstract data types and may be implemented using existinghardware at existing network elements. Such existing hardware mayinclude one or more Central Processing Units (CPUs), digital signalprocessors (DSPs), application-specific-integrated-circuits, fieldprogrammable gate arrays (FPGAs) computers or the like.

It should be borne in mind, however, that all of these and similar termsare to be associated with the appropriate physical quantities and aremerely convenient labels applied to these quantities. Unlessspecifically stated otherwise, or as is apparent from the discussion,terms such as “processing” or “computing” or “calculating” or“determining” of “displaying” or the like, refer to the action andprocesses of a computer system, or similar electronic computing device,that manipulates and transforms data represented as physical, electronicquantities within the computer system's registers and memories intoother data similarly represented as physical quantities within thecomputer system memories or registers or other such information storage,transmission or display devices.

Note also that the software implemented aspects of the exampleembodiments are typically encoded on some form of program storage mediumor implemented over some type of transmission medium. The programstorage medium may be any non-transitory storage medium such asmagnetic, optical, or flash memory, etc. Similarly, the transmissionmedium may be twisted wire pairs, coaxial cable, optical fiber, or someother suitable transmission medium known to the art. The exampleembodiments not limited by these aspects of any given implementation.

General Methodology

To ensure service level agreements (SLA) compliance for network slices,5G Service Providers (SPs) need reliable and cost-effective means forreal-time measurement and monitoring of latency. Passive methods forlatency measurement do not inject dedicated measurement traffic in thedata plane and do not modify the headers of user traffic. Serviceproviders can benefit from such passive methods because they do notinterfere with network performance and data usage-based chargingschemes. Relevant latency metrics include the end-to-end latency perslice between service endpoints, and the latency of traversal of partialsegments of the end-to-end network slice, such as individual virtuallinks, sub-slices, and virtual network functions. The latter providessignificant benefits in increasing a capability for troubleshooting,root-cause analysis, and implementation of corrective actions topreserve SLA guarantees. The instant example embodiments include asystem and method for passive, accurate, and scalable measurement oflatency for network slices.

Limited methods exist for latency measurement, but they are either (a)inadequate to meet the new requirements associated with 5G and thenetwork slicing concept, or (b) non-passive and intrusive in nature, andtherefore limited in applicability. The following is a representativeset of such techniques:

I. Active measurements: Using conventional diagnostic tools, the endhost or network node may inject special round-trip packets into thenetwork (a round-trip packet is a data packet that travels from a firstnetwork endpoint to a second network endpoint, and then returns to thefirst endpoint; the data in the packet may be modified as the packettravels in each direction, and also by the second endpoint beforetransmission to the first endpoint). Each returning round-trip packetcontains a timestamp of the original packet, and added timestamps canpossibly be added by a remote host and intermediate nodes. The sourceanalyzes the timestamps to infer latency information for the overall andpartial data paths. This method is not adequate for 5G network slicesand their stringent SLA key performance indicators (KPIs), for at leastthe following reasons.

A. The diagnostic tools involved are not passive: The injected packetsincrease the network load. While the load increase is typicallymarginal, there are cases where it can perturb the performance oflatency-sensitive applications and their KPI measures.

B. Designated new functions need to be installed on mobile end devicesspecifically to produce latency measurements and then signal themeasurement results to the network, which requires agreement of the endusers and pose a burden due to the sheer number of end devices.

C. In a network slicing environment, the packet probes of the latencymeasurement utilities do not undergo the same type of processing as thepackets of the applications that each slice is designed to support. Asprocessing contributes to latency, the measurements obtained from theprobes may be inaccurate.

II. TCP header inspection: Using a sequence number in a header oftransmission control protocol (TCP) data packets, and an acknowledgmentnumber in the header of the returning acknowledgment (ACK) packets, anintermediate network node, and not just the TCP source, can compute around-trip time to a TCP receiver. This method is only suitable forapplications that use TCP for end-to-end transport. Real-timeapplications with constrained latency requirements are unlikely to useTCP for end-to-end transport because of a delay added by TCP packetretransmissions. Transport protocols better tailored to the specificneeds of each application are likely to become commonplace, especiallyafter an introduction of industry quick user datagram protocol (UDP)internet connection protocol (i.e., QUIC protocol), as a shim layerabove UDP that allows a design of custom methods for network reliabilityand congestion control.

III. Deep packet inspection (DPI) or other methods for signature-basedpacket identification: Intermediate nodes can look deep into a packet(both header and payload) to identify packet flows and individualpackets and store per-flow and per-packet arrival/departure data. Aninter-node one-way latency sample can be computed by matching therecords collected at neighboring nodes for the same packet. Thisapproach faces the following challenges:

A. Large amounts of packet arrival/departure records need to be storedat each participating node and then transferred for matching. Randomlysampling only a fraction of the packets in transit does not work,because the latency calculation must compare event times at differentnodes for the same packet and the likelihood of sampling the same packetat different nodes is low if every node samples packets randomly andindependently of the other nodes.

B. The method is only suitable for the measurement of latency forsegments of a slice, and not of an end-to-end one-way latency of amulti-hop data path of a network slice.

The ability to configure overbooking of the shared network and computingresources by different slices is desirable for a communication networkoperator to enable maximum utilization of the network and therebymaximum return on the infrastructure investment.

Therefore, the example embodiments provide a system and a method thatincludes two types of distributed agents that may coordinate latencymeasurements of slices with a central node for designated networkslices, where the distributed agents may be associated either with linkswithin the communications network, or links that are used forcommunications that are external to the communication network. Themethod and system can compute (a) end-to-end slice latency and (b)latency for individual segments of the slice.

Specific Embodiments

The example embodiments consist of a system and method for a passivemeasurement of packet latency in a network slice, both for end-to-endlatency (between the slice endpoints), and within internal segments ofthe overall slice, where a segment may be a subnet of the slice, a link(physical or virtual) within the slice, a set of consecutive linkswithin the slice, a network node associated with the slice, or awell-defined network domain that is a part of the slice, etc. Thelatency measurements may be produced by a centralized element (alsoreferred to as a “central node,” or a “control node”) that controls andcoordinates periodic sampling by individual elements or nodes in thecommunication network, and periodically collects and correlates sets ofpacket timestamp records received from different sampling points of thenetwork. A packet timestamp record (also referred to as “timestampinformation”) may consist of a unique packet identifier and a timestampassociated with the time of record creation. A record is created forevery packet that traverses the sampling point during a recordcollection period. The comparison of the timestamps associated with thesame packet identifier in records received from different points in thenetwork yields a sample of the latency between the two points. Thecentralized element controls the duration of each record collectionperiod, the interval between collection periods, and the start time ofthe collection period at each point of the network involved in theprocess.

Some key elements of the example embodiments are summarized by thefollowing attributes:

I. Network-based: The example embodiments do not require theparticipation of end devices in the measurements.

II. Passive: The example embodiments do not involve an injection ofprobe packets, or a modification of the headers of transmitted packetsfor the system or method.

III. Scalable: The example embodiments rely on sampling transmittedpackets at intermittent time intervals that are compatible with theprocessing, storage, and transmission capacities of the nodes where thesampling occurs.

IV. Accurate: The example embodiments enable the fine-tuning of alatency measurement procedure based on characteristics of the data pathwhere it is applied.

Structural Embodiments

FIG. 1 illustrates the architecture of a system 100 for a communicationnetwork 50, in accordance with an example embodiment. The system 100 mayprovide latency measurements, and thereby obtain latency information.The system 100 may provide latency measurements (information) for apacket network that consists of a set of nodes {N-i}(10 a, 10 b, 10 c,20 a), a set of internal links {IL-j} (12 a, 12 b, 12 c, 12 d), and aset of external links {EL-k} (22 a). A node N-i may be a packet switch,a portion of a packet switch, a network function, a network capability,an application server or endpoint, or any other network element that iscapable of receiving and transmitting packets, with no restriction onscope and granularity. The nodes N-i may by instantiated as physicalstandalone entities or as virtualized entities, possibly sharing anunderlying infrastructure resource with other virtualized networkfunctions. An internal link IL-j connects two of the nodes within thecommunication network 50. An external link EL-k connects a node of thecommunication network 50 with a node that does not belong to thecommunication network 50. A wireless connection between a serving celland served end user device is an example of an external link 22 a. Bothinternal and external links may be either physical or virtual links.

The system 100 of the example embodiments includes the followingcomponents:

A. The Latency Measurement Engine (LME) 30: A centralized component (a“central node,” or “control node,” or Latency Measurement Engine “LME”)30 with a processor 300 a that controls the synchronization of sampling(start and duration) at different nodes (10 a, 10 b, 10 c and 20 a) toensure the timestamping of node traversal for a same set of packets. Theprocessor 300 a of the LME 30 collects and processes the latencymeasurements that originate from different points of the network 50.There generally may be one such engine (LME 30) per Operator Network(e.g. physical network or virtual network), though it should beunderstood that multiple LMEs 30 may be deployed within the sameinfrastructure or communication network 50, where the multiple LMEs 30may be shared by a plurality of virtual networks or network slices.

B. Type 1 Latency Measurement Agents (T1LMAs)—First-Type of NetworkNode: Distributed components (or network nodes/elements, designated asnodes 10 a, 10 b and 10 c in system 100) associated with the endpointsof internal links 12 a. They collect time-synchronized measurementsamples (a first type of measurement information) for one link 12 adirection, or for both directions of the link 12 a, and transmit thisinformation to the processor 300 of LME 30. Not all internal links of anetwork node are necessarily coupled with a T1LMA.

C. Type 2 Latency Measurement Agents (T2LMAs)—Second-Type of NetworkNode: Distributed components (or network nodes/elements, designated asnode 20 a in system 100) associated with the network endpoints ofexternal links 22 e (i.e., links whose second endpoint is outside thenetwork 50 and therefore not included in the measurement system). Anexample of an external link 22 e is a wireless access link, where theoutside endpoint is a mobile device (such as a user device/equipment)served by the network 50. T2LMAs collect measurement samples (a secondtype of measurement information) for one link 22 e direction, or forboth directions of the link 22 e, and transmit the measurementinformation to the processor 300 of LME 30. Not all external links of anetwork node are necessarily coupled with a T2LMA.

D. The LME 30 and all LMAs 10 a in the network 50: These components aresynchronized to a common time reference (i.e., a common “networkclock”). Any well-known method of causing this synchronization may beimplemented, where this synchronization and the details of itsimplementation are outside the scope of the instant described exampleembodiments.

Structural Example Embodiments

FIG. 2 illustrates a central (control) node 30, or LME 30, of the system100, in accordance with an example embodiment. The node 30 includesnetwork interfaces 304 (that may be wireless or wireline) to communicatewith other nodes in the system 100, signaling interfaces 306 (that maybe considered a “backhaul”) and a memory storage 302. The node 30 alsoincludes a processor 300 that may control the operations of the node 30.Some of these operations of the node 30 include: saving and retrievinginformation/data to and from the memory 302, transmitting signaling andinformation to other nodes in the system 100 using the interfaces304/306, and performing processing based at least in part oncomputer-readable instructions that are saved in the latency measurementcontrol module (LMCM) 300 a within the processor 300. Thecomputer-readable instructions in the LMCM 300 a may provideinstructions that cause the processor 300 to perform method steps fornode 30 that are commensurate with the steps that are described in theinstant method example embodiments in this document. It should beunderstood that the processor 300 also includes a physical (PHY) layer(with different configuration modes), a media access control (MAC) layer(with different configuration modes), a packet data convergence protocol(PDCP) layer (with different configuration modes), a user plane layer(with different configuration modes), a schedule and a radio linkcontrol (RLC) buffer, where these elements of the processor 300 are notshown in the drawings.

FIG. 3 illustrates a first measurement node 10 a, or T1LMAs, of thesystem 100, in accordance with an example embodiment. The node 10 aincludes network interfaces 204 to communicate with other nodes in thesystem 100, a backhaul interface 206 and a memory storage 202. The node10 a also includes a processor 200 that may control the operations ofthe node 10 a. Some of these operations of the node 10 a include: savingand retrieving information/data to and from the memory 202, transmittingsignaling and information to other nodes in the system 100 using theinterfaces 204/206, and performing processing based at least in part oncomputer-readable instructions that are saved in the latency measurementmodule Type 1 (LMMT1) 200 a within the processor 200. Thecomputer-readable instructions in the LMMT1 200 a may provideinstructions that cause the processor 200 to perform method steps fornode 10 a that are commensurate with the steps that are described in theinstant method example embodiments in this document. In an embodiment,the processor 200 may include a physical (PHY) layer (with differentconfiguration modes), a media access control (MAC) layer (with differentconfiguration modes), a packet data convergence protocol (PDCP) layer(with different configuration modes), a user plane layer (with differentconfiguration modes), a schedule and a radio link control (RLC) buffer,where these elements of the processor 300 are not shown in the drawings.

FIG. 4 illustrates a second measurement node 20 a, or T2LMAs, of thesystem 100, in accordance with an example embodiment. The node 20 aincludes network interfaces 404 to communicate with other nodes in thesystem 100, a backhaul interface 406, and a memory storage 402. The node20 a also includes a processor 400 that may control the operations ofthe node 20 a. Some of these operations of the node 20 a include: savingand retrieving information/data to and from the memory 402, transmittingsignaling and information to other nodes in the system 100 using theinterfaces 404/406, and performing processing based at least in part oncomputer-readable instructions that are saved in the latency measurementmodule Type 2 (LMMT2) 400 a within the processor 400. Thecomputer-readable instructions in the LMMT2 400 a may provideinstructions that cause the processor 400 to perform method steps fornode 20 a that are commensurate with the steps that are described in theinstant method example embodiments in this document. In an embodiment,the processor 400 may include a physical (PHY) layer (with differentconfiguration modes), a media access control (MAC) layer (with differentconfiguration modes), a packet data convergence protocol (PDCP) layer(with different configuration modes), a user plane layer (with differentconfiguration modes), a schedule and a radio link control (RLC) buffer,where these elements of the processor 300 are not shown in the drawings.

Use of Network Slice within the System

The system 100 includes the two types of distributed agents 10 a/20 athat may be coupled with Virtual Network Functions for collectinglatency related measurement samples pertaining to network slices (Type 1and Type 2 Latency Measurement Agents), and are in communication withthe centralized Latency Measurement Engine (LME) 30. The processor 300of the LME 30 coordinates sampling operations and processes the agentdata to compute (a) end-to-end slice latency and (b) latency forindividual segments of the slice.

In an embodiment, the method includes:

I. Coordinating data sampling, performed by different agents 10 a/20 a,by the processor 300 of the LME 30.

II. A framework for controlling agent 10 a/20 a sampling operations, viacontinuous adaptation of a duration and frequency of sampling periods,and based on the reported sample data collected at the processor 300 ofLME 30.

III. An algorithm or instructions for collecting sampling data andcomputing latency at the processor 300 of the LME 30 based on thecollected samples from the agents 10 a/20 a.

The example embodiment of the system and method makes it possible toestablish a reliable solution for latency measurement based on periodicsampling at advantageous points within a network slice, and enables a“best tradeoff” between an accuracy of the measurements and a signalingand processing burden that they impose on the communication network 50infrastructure.

In an example embodiment, the communication network may be a 5G network50 a that is a packet network. Therefore, FIG. 5 illustrates aninstantiation of the system 100 for latency measurement in arepresentative 5G communication network 50 a with multiple slices 600,602, 604, in accordance with an example embodiment. In particular, FIG.5 illustrates the instantiation of components of the example embodimentsfor three slices 600, 602, 604 that share a common physicalinfrastructure. The slices are coupled with a termination of a samephysical link, where LMAs (nodes 20 a, 20 b, 10 a, 10 b, etc.) may atany time belong to distinct slices 600, 602, 604 that are logicallyindependent but may be implemented as a single entity when associatedwith network functions that are shared by the multiple slices 600, 602,604. Each of the respective LMA nodes 10 a, 20 a may be grouped intoportions of the network 50 a, where the portions may include a 5G gNB(base station) 606 a, a 5G user plane function (UPF) 606 b, a layer 3(L3) router, and a layer 2 (L2) switch, as an example.

FIG. 5 illustrates that the three network slices 600, 602, 604 providedata paths between respective application servers 600 b, 602 b, 604 band client devices (UEs) 600 a, 602 a, 604 a. Each of the applicationservers 600 b, 602 b, 604 b belongs to a different respective slice 600,602, 604, where the application servers 600 b, 602 b, 604 b may provideservices or content to the respective UEs 600 a, 602 a, 604 a. For thisreason, the links between an application server 600 b and a respectiveL2 switch 606 d port are internal links, coupled with T1LMAs 10 q, 10 r(T1A-m,n is the n-th T1LMA of slice m). Meanwhile, the link between the5G gNB 606 a and the UE 600 a is an external links because the UE 600 ais not within the slice boundaries of the network 50 a, so the 5G gNB606 a endpoints of those links are coupled with T2LMAs 20 a (T2A-p,q isthe q-th T2LMA of slice p). Not all slices supported by the samephysical infrastructure are necessarily equipped with the latencymeasurement capabilities of the instant example embodiments. In FIG. 5,only the two top slices 600, 602 are. A single LME 30 may controlrespective LMAs 10 a, 20 a for the slices 600, 602 being monitored andcontrolled.

EXAMPLE EMBODIMENT OF THE METHOD Operation of Type 1 (Node 10 a) LMA

The processor 200 of the T1LMA (node 10 a) may start sampling packetsthat are received by the node 10 a following a period in time when thenode 10 a receives a trigger (request) message from the LME 30, wherethe sampled packets carry a given Network Slice ID (NSID) whichdesignates the identity of a designated slice. It should be noted thatthe nature and format of the NSID is not within the scope of the instantexample embodiments. Because the node 10 a is associated with a linkendpoint that handles traffic in two directions, a distinct trigger isrequired for each traffic direction, and therefore the NSID can specifythe traffic direction for sampling. The trigger includes the followingset of items (that denote the network slice ID, the sample start time,and the sample end time): <NSID, sample_start_time, sample_end_time,direction>. After receiving the trigger message, the processor 200 ofthe node 10 a processes all packets of the designated slice that arebeing transmitted in the specified direction that are received duringthe designated sample time-window. It is noted that the sampletime-window (sample_start_time and sample_end_time) should be a timeperiod that is in the future, as compared to a time of arrival of thetrigger message that is received by the node 10 a from LME 30. When theprocessor 200 of node 10 a processes a packet, it adds a packet reportrecord to a running log for the current sampling period. The packetreport record may contain at least the following items: <packet_ID,packet_size, timestamp>, where packet_ID may be a unique signatureidentifier for the packet, packet_size is a length of the packet thatmay be measured in bytes, and timestamp is a time of generation of thepacket report record according to the time reference shared by LME 30,node 10 a, and the other LMAs of the slice that is being monitored. Whenthe time reference reaches sample_end_time (i.e., the end of the sampletime-window) the processor 200 of node 10 a may stop creating packetreport records and send to the LME 30 the entire log accumulated for thesampling period.

Operation of Type 2 (Node 20 a) LMA

The T2LMA (node 20 a) is associated with a network endpoint for externallinks (links that communicate with nodes outside the network 50). Oneexample of an external link is a wireless access link for mobilewireless networks, where the link may be communicating with an end user(user equipment). One example of placement of the network endpoint ofthe wireless access link is a medium access control (MAC) layer of aradio access network (RAN) protocol stack. The MAC layer includes thescheduler for access to the wireless medium in both downlink (DL) anduplink (UL) directions. This section describes an instantiation of thenode 20 a in association with the wireless link scheduler of the RadioAccess Network.

FIG. 6 illustrates a system 100 a for latency measurement in a mobileradio access network (RAN) cell 50 b, in accordance with an exampleembodiment. The mobile RAN 50 b is shared by three network slices 610,620, 630 (with respective NSIDs denoted as a, b, and c). The descriptionthat follows focuses on an operation of the system 100 a for latencymeasurement specifically for slice 610 (with NSID a). T1A-a,1 (node 10b) and T1A-a,2 (node 10 a) are T1LMAs associated with the endpoint ofthe link that connects the RAN cell 50 b to the core network (T1A-a,1)and with the interface between radio link control (RLC) and MAC layersin the RAN protocol stack (T1A-a,2). The two T1LMAs may be implementedjointly with T1LMAs that serve other slices at the same data-pathpoints. T2A-a,1 (node 20 a) serves slice a in association with the MACscheduler (T2LMAs of other slices may be also implemented jointly).

The processor 400 of node 20 a computes a latency contribution of thewireless access link using information that it obtains from the MACscheduler at every transmission time interval (TTI). The information mayinclude the following data, where this description refers to a downlink(DL) data direction (though this type of data would be the same for theuplink (UL) data direction):

A. Aggregate physical resource block (PRB) rate PRB_agg(a, Δt, DL) forall DL bearers of slice a computed over time interval of duration Δt and(optionally) further averaged (or “smoothed”).

B. Average PRB rate PRB_avg(a, Δt, DL) for a virtual very active (VA) DLbearer of the slice a (where a ‘VA bearer’ almost always has dataavailable to send wirelessly). In one embodiment, PRB_avg(a, Δt, DL) maybe computed as described in U.S. Pat. No. 9,794,825, issued Oct. 17,2017, the entire contents of which is incorporated herein by referencein its entirety, and averaged over time interval Δt.

C. Average number of VA DL bearers NVA_avg(a, Δt, DL) in the slice. Inan embodiment, NVA_avg(a, Δt, DL) may be computed as described in U.S.Pat. No. 9,794,825, and averaged over time interval Δt.

It should be noted that PRB_agg(a, Δt, DL) represents the average amountof DL cell resources allocated to slice a, and PRB_avg(a, Δt, DL) andNVA_avg(a, Δt, DL) depend upon PRB_agg(a, Δt, DL) and uponapplication-dependent properties of the traffic flows in slice a.

The processor 400 of node 20 a computes the DL wireless link latencyL(a, D, Δt, DL) for D bits of slice a during a time interval Δt, whereΔt is the time it takes to transmit D bits at the average data rateobtained by a very active (VA) bearer of the slice. The same processor400 computes the UL wireless link latency L(a, D, Δt, UL).

If C(a, Δt, DL) is an average number of useful bits per PRB (notcounting retransmissions) allocated by the scheduler during a timeinterval Δt across all DL bearers of slice a, and computed as describedin E. Grinshpun et al., “Long-term application-level wireless linkquality prediction,” 36th IEEE Sarnoff Symposium, September 2015(available) which is incorporated by reference in its entirety into thisdocument, the processor 400 of node 20 a computes the DL wireless linklatency as follows:

L(a,D,Δt,DL)=D/(PRB_avg(a,Δt,DL)*C(a,Δt,DL))  Eq. 1

The equation for the UL latency is the following:

L(a,D,Δt,UL)=D/(PRB_avg(a,Δt,UL)*C(a,Δt,UL))  Eq. 2

In the equations Eq.1 and Eq.2 average latency independent of D may becomputed by selecting in Eq.1: D=D1+D2, where D1 is an average IP packetsize for the slice and D2 is an average size of the buffer accumulatingpackets before sending them over the link (e.g. average size of RadioLink Control (RLC) buffer).

The processor 400 of node 20 a computation for latency, as describedabove, is not CPU-intensive and does not require storage of largeamounts of data. The computation can therefore be performed continuouslyby the processor 400 of node 20 a. In an embodiment, the processor 300of LME 30 triggers the transmission of an up-to-date latency value witha data message that carries the following parameters: <NSID, D, Δt,direction>. The processor 300 of LME 30 sets D and Δt based on thetraffic SLAs of the slice, using larger values of D and Δt for sliceswith high expected traffic volume, and smaller values for slices withlow expected traffic volume. The processor 400 of node 20 a may alsosend its latency reports periodically, or upon a time in which aconfigured (determined) threshold is exceeded.

LME 30 Operation

The processor 300 of LME 30 receives the sample reports from the node 10a and node 20 a and combines them to compute the end-to-end latency foreach monitored slice and for selected portions of the data path withineach monitored slice. The processor 300 of the LME 30 sets the frequencyof the sampling periods for each node 10 a/20 a it controls and thestart and end times of the sampling periods for each node 10 a itcontrols.

FIG. 7 illustrates an operation of the first measurement node (node 10a), in accordance with an example embodiment. In particular, FIG. 7illustrates an example where the nodes of a network 50 c (similar to thenetwork 50 of FIG. 1), though this network 50 c involves virtualizednetwork function (VNF) instances 50 c 1/50 c 2. VNF X (50 c 1) and VNF Y(50 c 2) are shared by three slices 640, 650, 660 (with respectiveNSIDs, or “network slice identifiers,” that are denoted by a, b, and c).The description that follows focuses on slice a only, for which theprocessor 300 of LME 30 controls the operation of three node (nodes 10a, 10 b, 10 c) instances (specifically, nodes 10 a/10 b in VNF X, andnode 10 c in VNF Y). The T1LMAs of slice a may be instantiated asstandalone functions or jointly with T1LMAs of other slices that areassociated with the same link endpoints.

The respective processors 200 of nodes 10 a, 10 b, 10 c collect sets ofconsecutive packet report records based on the trigger messages thatthey receive from the processor 300 of LME 30, and send them to the LME30 as soon as the respective sampling periods reach their end times. Theprocessor 300 of LME 30 uses the sets of packet report records tocompute the latency of the data path from VNF X to VNF Y, where the datapath may consist of a single link (possibly virtual), or multipleconcatenated links, possibly joining other VNF instances.

Scalability requires the duration H of the T1LMA sampling periods to beas short as possible. However, shortening the sampling periods reducesthe size of the intersection of the sets of packet identifiers collectedat the endpoints of the latency measurement path. As the processor 300of the LME 30 keeps collecting sets of packet report records, theprocessor 300 of the LME 30 can fine-tune both the durations and thestart times of the sampling periods at the measurement endpoints toincrease the size of the intersection set.

In an embodiment, the processor 300 of the LME 30 uses the followingmethod to control the parameters of the sampling periods when measuringthe latency between the endpoints of the measurement data path.

First, the processor 300 of the LME 30 must set the start and end timesof the sampling periods at the T1LMAs of the measurement path endpoints.Let t(a, 2, start) be the start time of the sampling period at T1A-a,2(in VNF X), and t(a, 3, start) be the start time of the sampling periodat T1A-a,3 (in VNF Y). The end times of the same periods are t(a, 2,end) and t(a, 3, end). Accordingly, the durations of the samplingperiods at the two T1LMAs are H(a, 2)=t(a, 2, end)−t(a, 2, start), andH(a, 3)=t(a, 3, end)−t(a, 3, start). Let E(a, 2, 3) be the expectedlatency from T1A-a,2 to T1A-a,3 based on the most recent measurements,and S(a, 2, 3) a small fraction of E(a, 2, 3) (e.g., S(a, 2, 3) may bedefined as the product of a configurable factor and the standarddeviation of the same sample that yields the average E(a, 2, 3)). Theprocessor 300 of the LME 30 sets the start and end times at thedownstream T1LMA as follows:

t(a,3,start)=t(a,2,start)+E(a,2,3)−S(a,2,3),

t(a,3,end)=t(a,3,start)+H(a,2)+S(a,2,3).  Eq. 3

In this way the duration of the sampling interval H(a, 3) at thedownstream T1LMA (T1A-a,3) is longer than the interval H(a, 2) at theupstream T1LMA (T1A-a,2) by 2*S(A, 2, 3).

Next, the processor 300 of the LME 30 must compute the latency fromT1A-a,2 to T1A-a,3 using the sets of packet report records received fromthe two T1LMAs.

FIG. 8 illustrates a method of the central node (LME) 30, in accordancewith an example embodiment. In particular, FIG. 8 describes a method ofoperation of the LME 30 in conjunction with T1LMAs T1A-a,2 and T1A-a,3,including the processing of the packet report record sets forcontrolling the sampling parameter H and S and for computing the averagelatency E. As stated above, the LMCM 300 a, LMMT1 and LMMT2 may includecomputer-readable instructions for the respective processors 300, 200,400 (for the LME 30, node 10 a and node 20 a) to perform the steps ofthis method.

In step S600, the processor 300 of LME 30 may commence the method bydetermining that latency measurements and latency control measures areneeded. This start to the method may be accomplished on a regularperiodic schedule, a command from a mother node, a manual command from anetwork operator, based on an operator policy associated with a networkevent such as an addition or reconfiguration of a network slice, adetected degradation of application quality of experience, detectednetwork congestion, etc.

In step S602, the controller 300 sends sample triggers (requestmessages) to node in the network 50. The nodes may be to a node 10 awithin the network 50, or the nodes may also be nodes 20 a that havelinks that extend outside of the network 50. Once the nodes 10 a and/or20 a receive the request message, they take measurements and compilepacket reports commensurate with the example embodiments describedabove.

In step S604, the processor 300 of LME 30 receives the packet reportsfrom nodes 10 a and/or 20 a, and in step S606 the processor 300determines matching signatures (as described above), where thisdetermination may also involve determining a threshold numerical valuequantifying a number of matches. The threshold numerical value may, forinstance, be a total number of matches.

If in step S606 the processor 300 determines that enough matches arepresent, then in step S608 the processor 300 may compute latencyinformation, or otherwise investigate latency information, for thematches. Specifically, the processor 300 may compute latency and controlparameters, where the latency and control parameters may be forend-to-end latency, or a latency of slice segment within the end-to-endtransmission (as described above). In an embodiment, processor 400 fornode 20 a may optionally determine this latency information and thensend the latency information to the LME 30, as opposed to the processor30 of LME 30 determining the latency information. And therefore, in stepS608 the processor 300 may analyze the latency information for thematches. In an embodiment, in step S608, the processor 300 may controlan operation of the network in response to the latency analysis. Thismay be accomplished by re-routing slices through different nodes,re-routing slices through different configurable layers (PHY layer, MAClayer, PDCP layer, user plane layer) of a same node and/or changing thesettings of these layers, re-routing slices through differentconfigurable modes of the scheduler and/or RLC of the same node and/orchanging the settings of the scheduler and/or RLC, notifying networknodes to adjust settings, increase or decrease network throughput, etc.,where these actions to control an operation of the network mayoptionally be coordinated with other LMEs 30, a central office for thenetwork (not shown in the drawings), or otherwise coordinated with anumber of nodes within the network 50 or even nodes outside of thenetwork 50. Following step S608 the method may be repeated (where themethod resorts back to step S602).

If in step S606 the processor 300 determines that not enough matches arepresent, then in step S6610 the processor 300 of LME 30 may increaseH(a, 2) and S(a, 2, 3), with a purpose of increasing a number of matchesduring another iteration of the method. Following step S610 the methodmay be repeated (where the method resorts back to step S602).

The processor 300 of LME 30 may disable the collection of packet reportrecords from intermediate T1LMAs when the latency measurements betweenthe slice endpoints are stable, and activate it again when the latencymeasurements increase or when the sets of packet report records from theslice endpoints become severely misaligned, with only little or nullintersection.

The processor 300 of LME 30 computes the latency of individual packetsbetween two T1LMAs by matching their identifiers (signatures) in therespective sets and subtracting their timestamps. The processor 300 ofLME 30 accumulates the latency samples in combined metrics (e.g., anaverage of choice) and further normalizes them. The type ofnormalization depends on the traffic properties of the slice traffic.For example, for slices with consistently high volume of traffic thenormalization may be done over a reference data unit size D; forlow-volume bursty traffic, instead, the normalization may be done overthe number of packets processed during a time Δt.

It should be understood that the nodes of the example embodimentsdescribed herein can be physical or virtual routers, switches, 4Gwireless eNodeBs, SGW, PGW, MME, 5G wireless nodes (gNodeB, UPF,),gateways, or other structural elements that are capable of fulfillingthe functions and method steps outline in this document.

Although depicted and described herein with respect to embodiments inwhich, for example, programs and logic are stored within the datastorage and the memory is communicatively connected to the processor, itshould be appreciated that such information may be stored in any othersuitable manner (e.g., using any suitable number of memories, storagesor databases); using any suitable arrangement of memories, storages ordatabases communicatively connected to any suitable arrangement ofdevices; storing information in any suitable combination of memory(s),storage(s) or internal or external database(s); or using any suitablenumber of accessible external memories, storages or databases. As such,the term data storage referred to herein is meant to encompass allsuitable combinations of memory(s), storage(s), and database(s).

The description and drawings merely illustrate the principles of theexample embodiments. It will thus be appreciated that those skilled inthe art will be able to devise various arrangements that, although notexplicitly described or shown herein, embody the principles of theinvention and are included within its spirit and scope. Furthermore, allexamples recited herein are principally intended expressly to be onlyfor pedagogical purposes to aid the reader in understanding theprinciples of the invention and the concepts contributed by theinventor(s) to furthering the art, and are to be construed as beingwithout limitation to such specifically recited examples and conditions.Moreover, all statements herein reciting principles, aspects, andembodiments of the invention, as well as specific examples thereof, areintended to encompass equivalents thereof.

The functions of the various elements shown in the example embodiments,including any functional blocks labeled as “processors,” may be providedthrough the use of dedicated hardware as well as hardware capable ofexecuting software in association with appropriate software. Whenprovided by a processor, the functions may be provided by a singlededicated processor, by a single shared processor, or by a plurality ofindividual processors, some of which may be shared. Moreover, explicituse of the term “processor” or “controller” should not be construed torefer exclusively to hardware capable of executing software, and mayimplicitly include, without limitation, digital signal processor (DSP)hardware, network processor, application specific integrated circuit(ASIC), field programmable gate array (FPGA), read only memory (ROM) forstoring software, random access memory (RAM), and non-volatile storage.Other hardware, conventional or custom, may also be included.

Example embodiments may be utilized in conjunction with varioustelecommunication networks and systems, such as the following (wherethis is only an example list): Universal Mobile TelecommunicationsSystem (UMTS); Global System for Mobile communications (GSM); AdvanceMobile Phone Service (AMPS) system; the Narrowband AMPS system (NAMPS);the Total Access Communications System (TACS); the Personal DigitalCellular (PDC) system; the United States Digital Cellular (USDC) system;the code division multiple access (CDMA) system described in EIA/TIAIS-95; a High Rate Packet Data (HRPD) system, Worldwide Interoperabilityfor Microwave Access (WiMAX); Ultra Mobile Broadband (UMB); 3^(rd)Generation Partnership Project LTE (3GPP LTE); and 5G networks.

Example embodiments having thus been described, it will be obvious thatthe same may be varied in many ways. Such variations are not to beregarded as a departure from the intended spirit and scope of exampleembodiments, and all such modifications as would be obvious to oneskilled in the art are intended to be included within the scope of thefollowing claims.

1-23. (canceled)
 24. A method of controlling an operation of acommunication network, comprising: transmitting, by at least one firstprocessor of a central node, request messages to at least one firstnetwork node, the request messages each including at least a samplingtime-window and a network slice identifier, the sampling time-windowdefining a duration of time, the network slice identifier identifying adesignated network slice within the communication network; receiving, atthe at least one first processor, packet reports from the at least onefirst network node, the packet reports including latency information forpackets that are processed by the at least one first network node duringthe sampling time-window for the designated network slice; andcontrolling, by the at least one first processor, the operation of thecommunication network based on the latency information.
 25. The methodof claim 24, wherein the at least one first network node includes atleast one first-type of network node with a first link in the designatednetwork slice, the first link having a termination endpoint that iswithin the communication network.
 26. The method of claim 24, whereinthe at least one first network node includes at least one second-type ofnetwork node with a second link in the designated network slice, thesecond link having a termination endpoint that is outside the designatednetwork slice.
 27. The method of claim 25, wherein the receiving of thepacket reports includes, receiving, from the first-type of network node,a first-type of packet reports for the designated network slice, thefirst-type of packet reports each including, packet identifierinformation, packet size information, and timestamp information.
 28. Themethod of claim 26, wherein the at least one first network node includesat least one first-type of network node with a first link in thedesignated network slice, the first link having a termination endpointthat is within the communication network, and the receiving of thepacket reports includes, receiving, from the first-type of network node,a first-type of packet reports for the designated network slice, thefirst-type of packet reports each including, packet identifierinformation, packet size information, and timestamp information; andreceiving, from the second-type of network node, a second-type of packetreports for the designated network slice, the second-type of packetreports each including latency information for the second-type ofnetwork node.
 29. The method of claim 24, wherein the network sliceidentifier identifies a direction of communication for the designatednetwork slice, the direction being one of an uplink direction and adownlink direction.
 30. The method of claim 27, wherein the central nodeand the first-type of network node are synchronized to a same networkclock for the communication network, and the request messages to the atleast one first-type of network node includes a start time defined bythe sampling time-window.
 31. The method of claim 30, wherein the atleast one first-type of network node includes a downstream first-type ofnetwork node and an upstream first-type of network node, thetransmitting of the request messages including, transmitting a firstrequest message with a first sampling time-window to the downstreamfirst-type of network node, the first sampling time-window defining afirst start time and a first duration of time, and transmitting a secondrequest message with a second sampling time-window to the upstreamfirst-type of network node, the second sampling time-window defining asecond start time and a second duration of time, the first duration oftime being one of the same and different than the second duration oftime.
 32. The method of claim 31, wherein the receiving of the packetreports includes, receiving a first packet report from the downstreamfirst-type of network node, the first packet report including one firstset of packet identifier information associated with one first set oftimestamp information, and receiving a second packet report from theupstream first-type of network node, the second packet report includingone second set of packet identifier information associated with onesecond set of timestamp information.
 33. The method of claim 32, furthercomprising: calculating the latency information by, matching identifierinformation between the one first set of packet identifier informationand the one second set of packet identifier information to arrive at amatched subset of identifier information, and determining a differencebetween a first portion of the one first set of timestamp informationand a second portion of the one second set of timestamp information, thefirst and second portions being associated with the matched subset ofidentifier information.
 34. A method of controlling an operation of acommunication network in a system, the system including a central nodeand at least one first network node, the method comprising:transmitting, by at least one first processor of the central node,request messages to at least one second processor of the at least onefirst network node, the request messages each including at least asampling time-window and a network slice identifier, the samplingtime-window defining a duration of time, the network slice identifieridentifying a designated network slice within the communication network;creating, by the at least one second processor, packet reports uponreceipt of the request message, the packet reports including latencyinformation for packets that are processed by the at least one firstnetwork node during the sampling time-window for the designated networkslice; receiving, at the at least one first processor, the packetreports from the at least one second processor; and controlling, by theat least one first processor, the operation of the communication networkbased on the latency information.
 35. The method of claim 34, whereinthe at least one first network node includes at least one first-type ofnetwork node with a first link in the designated network slice, thefirst link having a termination endpoint that is within thecommunication network.
 36. The method of claim 34, wherein the at leastone first network node includes at least one second-type of network nodewith a second link in the designated network slice, the second linkhaving a termination endpoint that is outside the designated networkslice.
 37. The method of claim 35, wherein the receiving of the packetreports includes, receiving, from the first-type of network node, afirst-type of packet reports for the designated network slice, thefirst-type of packet reports each including, packet identifierinformation, packet size information, and timestamp information.
 38. Themethod of claim 36, wherein the at least one first network node includesat least one first-type of network node with a first link in thedesignated network slice, the first link having a termination endpointthat is within the communication network, and the receiving of thepacket reports includes, receiving, from the first-type of network node,a first-type of packet reports for the designated network slice, thefirst-type of packet reports each including, packet identifierinformation, packet size information, and timestamp information; andreceiving, from the second-type of network node, a second-type of packetreports for the designated network slice, the second-type of packetreports each including latency information for the second-type ofnetwork node.
 39. The method of claim 34, wherein the network sliceidentifier identifies a direction of communication for the designatednetwork slice, the direction being one of an uplink direction and adownlink direction.
 40. The method of claim 37, wherein the central nodeand the first-type of network node are synchronized to a same networkclock for the communication network, and the request messages to the atleast one first-type of network node includes a start time defined bythe sampling time-window.
 41. The method of claim 40, wherein the atleast one first-type of network node includes a downstream first-type ofnetwork node and an upstream first-type of network node, thetransmitting of the request messages including, transmitting a firstrequest message with a first sampling time-window to the downstreamfirst-type of network node, the first sampling time-window defining afirst start time and a first duration of time, and transmitting a secondrequest message with a second sampling time-window to the upstreamfirst-type of network node, the second sampling time-window defining asecond start time and a second duration of time, the first duration oftime being one of the same and different than the second duration oftime.
 42. The method of claim 36, wherein the creating of the packetreports includes, calculating, by the at least one second processor ofthe at least one second-type of network node, physical resource block(PRB) rate information and bearer information that includes aquantification of a number of very active bearers, and determining, bythe at least one second processor, the latency information based on thePRB rate information and the bearer information.
 43. A central node,comprising: a memory storing computer-readable instructions; and atleast one first processor configured to execute the computer-readableinstructions such that the at least one first processor is configuredto, transmit request messages to at least one first network node, therequest messages each including at least a sampling time-window and anetwork slice identifier, the sampling time-window defining a durationof time, the network slice identifier identifying a designated networkslice within a communication network, receiving packet reports from theat least one first network node, the packet reports including latencyinformation for packets that are processed by the at least one firstnetwork node during the sampling time-window for the designated networkslice, and control an operation of the communication network based onthe latency information.